Many methods of image sharpening exist and are ubiquitous in many applications including consumer, medical and law enforcement applications. The need for image sharpening is ever increasing in these areas, particularly in medical applications, where improved image quality is greatly desired to make such systems and devices more efficient and effective at providing results. Recently, the concept of sharpness transport across color channels has been introduced in order to improve the sharpness of images in any and all of these applications. This concept has recognized that the utilization of sharpness from all color channels of a single color image can lead to improved images. As a result, it tends to produce a more natural appearance than traditional sharpening, such as de-convolution for example. It also avoids potential motion issues encountered by other methods that require more than one image for producing a sharp image.
However, implementations of this concept are complex and expensive in practice. In these applications, the key parameters used for sharpness transport, such as the weighting coefficients, depend on lens data or calibration experiments. Furthermore, the weighting coefficients need to be determined for values of the influent parameters, such as position within the image field, object distance, light spectrum, and other parameters. In one prior system with RGB color images, a high pass filter (HP) is represented in two different channels as HPi(Cj) to denote high pass filters applied on color channel j and added to channel i with a weighting coefficients WijCi,Out=Ci,In+WiRHP(CR)+WiGHP(CG)+WiBHP(CB)
For many real-time applications such as surgical applications, the constant change of imaging targets and surrounding objects may require live calibration of different parameters. Addressing this need may hinder the wider application of sharpness transport. As a result, there is a need for efficient implementations that enable many real-time applications. In addition, simple sharpness transport such as those in current applications may not provide adequate sharpness improvement to provide the desired results. Also, there is a potential issue of color contamination in simple sharpness transport that would obscure an image, where color values could be borrowed from other channels along with sharpness, resulting in a sharper but color-altered image.
Thus, there exists a need in the art for improved systems and processes for sharpening color images that does not depend on lens data or calibration experiments, and that does not require weighting coefficients to be determined for each value of the influent parameters. As will be seen, the invention provides such systems and processes and in an elegant manner.